Riche:Cloudchaser Sakonige the Red Wolf: Seriously, what purpose does searching the skies for "killer asteroids" serve? Suppose that astronomers see one 1km wide that will hit Hong Kong in 30 earth days. What's the plan? I don't see the point in watching for a potential problem without also having a plan to deal with that problem

Are you shiatting us?

Given 30 days warning, you could get a lot of people out of Hong Kong. Hell, you probably could get everybody out and safely away if you could somehow keep them from panicking.

You not only have to get people out if Hong Kong, you have to get people out of Hong Kong(Including the crictically ill who shouldn't be moved from hospitals) and anything for hundreds of miles surrounding it.Strike zone area is not completely predictable, debris field could be massive. Suddenly it's moving a lot of people really far away in a very short time frame. If you're calculations are even slightly off, people could be moved into harms way instead of out of it. That's the dilemma.

kertus:With luck, Mars is going to get smacked with a big one. That MIGHT get some people to wake up and realize that we need to get moving on this issue

The push wouldn't last long enough to actually do anything but generate campaign photos. Shoemaker-Levy 9 left impact zones the size of Earth and nothing came of it in terms of actually addressing the issue. Politicians don't care unless they can see it coming and coming at them specifically. See the Cuban Missile Crisis for an example.

generallyso:kertus: With luck, Mars is going to get smacked with a big one. That MIGHT get some people to wake up and realize that we need to get moving on this issueThe push wouldn't last long enough to actually do anything but generate campaign photos. Shoemaker-Levy 9 left impact zones the size of Earth and nothing came of it in terms of actually addressing the issue. Politicians don't care unless they can see it coming and coming at them specifically. See the Cuban Missile Crisis for an example.

With Shoemaker-Levy, we saw a few big bangs and some holes in the clouds. Not naturally having a good sense of scale, people didn't viscerally realize how huge of a thing it really was. Seeing a terrestrial planet get smacked up by an asteroid, especially with probes on the ground and in orbit that can beam back nice pictures of the damage, is something that I think would affect people in a much bigger way.

generallyso:kertus: With luck, Mars is going to get smacked with a big one. That MIGHT get some people to wake up and realize that we need to get moving on this issueThe push wouldn't last long enough to actually do anything but generate campaign photos. Shoemaker-Levy 9 left impact zones the size of Earth and nothing came of it in terms of actually addressing the issue. Politicians don't care unless they can see it coming and coming at them specifically. See the Cuban Missile Crisis for an example.

Agreed, but we have a relationship with Mars, we landed on it, it's 'ours'... Jupiter is too far away to generate any emotional consequence. If Mars gets thumped and we lose all our satellites there, and the 'cute' and scrappy little rovers - it'll be a cosmic 9/11

Mad_Radhu:Vitamin Pb: You do realize we don't actually have the capability to launch a nuke at a moving astroid, right? If you got really lucky, you could hit it with an ICBM in atmosphere (way too late) or possible in LEO, but really at that point you are just randomizing where it will hit.

(The max we can loft out of orbit is a few hundred pounds. And that takes 5-20 years of work.)

LOLWHUT?

The entire Mars Science laboratory spacecraft was 8,580 lb, which is lighter than a 9 Mt W53 warhead used on the Titan IIs by about 2000 lbs, which gives you about 2000 lbs to play with for the actual delivery spacecraft (maybe more if you could strip some weight of the bomb in terms of head and radiationshielding) if you used the same Atlas V that the MSL did and you were aiming at an asteroid in a near-earth orbit.

To put it another way: the energy needed to get an object into an Earth-Moon transfer orbit is just a hair short of the energy needed to get it into an Earth escape orbit. If you think you can get a nuclear warhead lighter than the Lunar lander, rebuilding the Saturn V will do nicely.

The main challenge is that you need to observe the target object really precisely to hit it with such a relatively low-energy transfer orbit. It's a bit trickier than hitting, say, Mars.

...And to do that, you need to be watching the skies closely enough to see it coming in plenty of time. Which leads us back to the point of TFA,

Thinking about a long term threat that is maybe 500 or 1000 years away is for an advanced, civilized society. The fact that this is even debated shows a lot. If 100 people die per year in airplane accidents, then over 100,000 years there would be 10 billion deaths. An asteroid large enough to kill humanity (est: 10 billion) comes roughly every 100,000 years. We don't have trouble imagining the degree of the threat, it's the timeframe which it can happen and shortsightedeness that limits us.

Hey, telling us we are all going to die in a few days to weeks is about all NASA is good for anymore, they sure cant leave the earth now. I say take half the money we give NASA and give it to the folks over at SpaceX. We'd have a man on mars before the end of the decade I bet

Actually- with enough warning, we can do a lot.1- As far out as we're tracking these things, it only takes a little nudge to push one from a collision trajectory to an orbit (if we feel like showing off) or clean miss. The math involved isn't even that hard.2- Even closer in, diverting them to make sure they burn up on entry instead of ground-pound... not hard either.3- Even closer in, figuring out where they're going to hit with a couple week's notice could let us save a lot of lives. As others have pointed out, probably not all- but any is better than none.

All pretty easily done. Think about the number of satellites in orbit right now (in the low to mid 10,000's, depending on whose data you're looking at, and whether you're looking at active ones or space junk)... and tell me we don't have rockets enough to manage a rush launch if we found something headed for us a few weeks away.And all we need is a nudge. Nothing spectacular, or even high-tech... just smack the thing in one side, and watch it whiz into the moon instead of us. Sirius may be a little mad we co-opted their newest satellite for a ballistic missile, but oh well.

Right now (last I saw), the NEO program had eyes on about 10-20% of what we estimate to be out there- and by that, I mean that we had managed to track and calculate trajectories for those objects with enough accuracy that as long as they don't interact with any of the other 90%, we could predict their behavior going forward for decades. Of that 10-20%, 1,300 or so have been labeled as potentially threatening at some point (large and near enough trajectories to worry us)... but since that other 90% is out there, there's a decent chance any one of them could go careening off neatly away from us, or collide with something else... or have 11,700 buddies waiting to join in.[On the upside, we've cataloged almost 98% of all NEO's over 1km in diameter, but those are just the literal planet-killers.]Sounds scary, sure... but it's not that bad.

What NASA's been asking for- for years and years, I might add- is increased funding so we can catalog that other 90% as quickly as possible. Once we have a complete picture, we can (theoretically) build a perfect model and stop watching altogether (except to occasionally check in and make sure our model is still correct. Orbital physics is very well understood, by and large).Moreover, we could then start modifying the model- adding little nudges here and there, to make it so those threats settle neatly into something's orbit, and well away from us.

The real problem here is the way the sequester works- it forces every government program, project or activity to be cut by 8%.That doesn't mean NASA gets cut by 8%, and can choose to, say, fire a few janitors and keep all their science programs.It means... every program they have gets cut. By the same amount. [It seems they got a partial exemption, to the effect of 5%, not 8%... but it works the same.]Current funding is around $20M, by the most recent figures I could find. A 5% cut drops it to $19M.

It's worth noting, first of all, that Congress mandated that they had to have over 90% of all NEO's between 140m and 1km cataloged by 2020. (As a reference, Tunguska was about 100m, and equivalent to a 10 megaton blast, flattening 2000 sq km/770 sq miles of territory).So... this isn't frivolous. They've been ordered by congress to do this or else. The $20M would allow them to meet goals in 2030, and now instead of increased funding, it's getting cut even further.

It's also worth noting that if every single American adult were willing to donate $0.06 to the project, it would double their budget. A one-time donation of $0.50 from each would be enough to double their budget from now until 2020, and complete the project easily in time.

ARedthorn:Actually- with enough warning, we can do a lot.1- As far out as we're tracking these things, it only takes a little nudge to push one from a collision trajectory to an orbit (if we feel like showing off) or clean miss. The math involved isn't even that hard.2- Even closer in, diverting them to make sure they burn up on entry instead of ground-pound... not hard either.3- Even closer in, figuring out where they're going to hit with a couple week's notice could let us save a lot of lives. As others have pointed out, probably not all- but any is better than none.

All pretty easily done. Think about the number of satellites in orbit right now (in the low to mid 10,000's, depending on whose data you're looking at, and whether you're looking at active ones or space junk)... and tell me we don't have rockets enough to manage a rush launch if we found something headed for us a few weeks away.And all we need is a nudge. Nothing spectacular, or even high-tech... just smack the thing in one side, and watch it whiz into the moon instead of us. Sirius may be a little mad we co-opted their newest satellite for a ballistic missile, but oh well.

Right now (last I saw), the NEO program had eyes on about 10-20% of what we estimate to be out there- and by that, I mean that we had managed to track and calculate trajectories for those objects with enough accuracy that as long as they don't interact with any of the other 90%, we could predict their behavior going forward for decades. Of that 10-20%, 1,300 or so have been labeled as potentially threatening at some point (large and near enough trajectories to worry us)... but since that other 90% is out there, there's a decent chance any one of them could go careening off neatly away from us, or collide with something else... or have 11,700 buddies waiting to join in.[On the upside, we've cataloged almost 98% of all NEO's over 1km in diameter, but those are just the literal planet-killers.]Sounds scary, sure... but it's not that bad.

What NASA's been asking for- for years and years, I might add- is increased funding so we can catalog that other 90% as quickly as possible. Once we have a complete picture, we can (theoretically) build a perfect model and stop watching altogether (except to occasionally check in and make sure our model is still correct. Orbital physics is very well understood, by and large).Moreover, we could then start modifying the model- adding little nudges here and there, to make it so those threats settle neatly into something's orbit, and well away from us.

The real problem here is the way the sequester works- it forces every government program, project or activity to be cut by 8%.That doesn't mean NASA gets cut by 8%, and can choose to, say, fire a few janitors and keep all their science programs.It means... every program they have gets cut. By the same amount. [It seems they got a partial exemption, to the effect of 5%, not 8%... but it works the same.]Current funding is around $20M, by the most recent figures I could find. A 5% cut drops it to $19M.

It's worth noting, first of all, that Congress mandated that they had to have over 90% of all NEO's between 140m and 1km cataloged by 2020. (As a reference, Tunguska was about 100m, and equivalent to a 10 megaton blast, flattening 2000 sq km/770 sq miles of territory).So... this isn't frivolous. They've been ordered by congress to do this or else. The $20M would allow them to meet goals in 2030, and now instead of increased funding, it's getting cut even further.

It's also worth noting that if every single American adult were willing to donate $0.06 to the project, it would double their budget. A one-time donation of $0.50 from each would be enough to double their budget from now until 2020, and complete the project easily in time.

*facepalm*

Though I agree with most of that, I don't think there is any point in which we can just stop looking, at least not until detection/defense can be fully automated.

The affect of gravity from nearby bodies can be too variable to effectively model. Consider tides - the influence of the moon and sun interact based on relative position to have different affects. Whether it be the sun causing outgassing of a comet as it passes or something passing by Jupiter, at the very best we could predict when we need to reobserve and remodel orbits.

Mytch:Though I agree with most of that, I don't think there is any point in which we can just stop looking, at least not until detection/defense can be fully automated.The affect of gravity from nearby bodies can be too variable to effectively model. Consider tides - the influence of the moon and sun interact based on relative position to have different affects. Whether it be the sun causing outgassing of a comet as it passes or something passing by Jupiter, at the very best we could predict when we need to reobserve and remodel orbits.

Yeah- keeping an eye out at least to recheck our models, make sure they're still accurate is a must. My point was more that once a good catalog and model has been built, the heavy lifting is over- and a lot of the funding could be shifted elsewhere if need be: to, for example, giving those nudges as needed (something I think everyone will agree is money well spent, if we find the wrong kind of rock out there)... or studying them, or even mining them. I recall the net worth of the raw materials of DA-14 being something on the order of several trillion... it's just a bit beyond us to do anything about or with.

Anyhow- NASA's not exactly asking for lots of money here... especially considering they're being ordered to do this on a deadline by the same guys pulling the funding. So much facepalm. So much.